Anti- and Pro-Oxidant Properties of Cerium Oxide Nanoparticles Functionalized with Gallic Acid

Cerium oxide sols functionalized with gallic acid (GA) in various molar ratios (CeO2@GA, 1 : 1, 1 : 2, and 2 : 1) were synthesized for the first time. The antioxidant activity of the obtained nanomaterials towards alkylperoxyl radicals was analyzed by the luminol-enhanced chemiluminescence assay. It was shown that CeO2@GA composites possess different types of redox activity, combining antioxidant and pro-oxidant properties. It was found that the redox activity of CeO2@GA composites is largely due to the ligand, gallic acid. Meanwhile, the immobilization of gallic acid on the surface of cerium dioxide nanoparticles leads to a decrease in its antioxidant and pro-oxidant activities. This effect is most pronounced in the case of the 2 : 1 CeO2@GA sol, in which the antioxidant and pro-oxidant capacities of gallic acid have decreased by 40 +/- 3 and 58 +/- 9%, respectively.

Automated summary

Cerium oxide sols functionalized with gallic acid were synthesized, and it was found that these composites possess antioxidant and pro-oxidant properties. The immobilization of gallic acid on the surface of cerium dioxide nanoparticles leads to a decrease in its antioxidant and pro-oxidant activities, especially in the 2:1 ratio.